The present invention relates to a sealing structure of cavities containing solutions on a reagent tray for suppressing evaporation of the solutions during thermal reaction.
FIG. 7 shows the conventional sealing structure of the reagent tray. A tray 70 has a plurality of cavities 71 which contain solution 72. The cavities 71 have openings along a face of the tray 70 at varying levels. A flat sealing member 73 is disposed on the tray 70 to cover the cavity openings. The flat sealing member 73 is composed of an elastic sheet. A presure plate 74 is disposed on the sealing member 73 to apply pressure to the sealing member 73 to seal the cavity opening. The set of tray 71, sealing member 73 and pressure plate 74 is heated by a pair of heaters 75 and 76 to effect thermal reaction of the solution 72 within each cavity 71.
However, the sealing member 73 cannot tightly seal all of the cavities 71 due to the varying levels of the cavity openings. Thus, some of the solution may evaporate during the thermal reaction to thereby hinder the uniform reaction throughout the cavities.